Explain: Converting Sunlight into Sugar

1. Explain: Converting Sunlight into Sugar • Photosynthesis is the process by which plants use the sun’s energy to convert water and carbon dioxide into sugars. • Read “Energy” p. 327 – 329 • Take Notes!

2. Explain: Converting Sunlight into Sugar • Energy is the ability to do work. • Kinetic energy is the energy of motion • Potential energy is energy that is stored due to an object’s position or arrangement. • Energy can be converted from one form to another. • Different types of energy – chemical, light, electrical, mechanical, thermal

3. Explain: Converting Sunlight into Sugar • Organic molecules have a form of potential energy called chemical energy • Chemical energy has the potential to do work due to the arrangement of the atoms within the molecules. • The rearrangement of atoms during chemical reactions releases the potential energy, and the energy is then available to do work.

4. Explain: Converting Sunlight into Sugar

5. Explain: Converting Sunlight into Sugar • Photosynthesis is the process by which plants use the sun’s energy to convert water and carbon dioxide into sugars. • Light is the only source of energy for plants! • Plants convert light energy into chemical energy -> Photosynthesis • Recall that light is energy • Different colors of light have different wavelengths and different amounts of energy. • Red light = low energy • Blue light = high energy

6. Explain: Converting Sunlight into Sugar Light is a form of energy called Electromagnetic energy.

7. Explain: Converting Sunlight into Sugar • A substance’s color is due to chemical compounds called pigments. • When light hits an object the wavelengths can be transmitted, absorbed, or reflected.

8. Explain: Converting Sunlight into Sugar • Chloroplasts contain pigments called Chlorophyll a, Chlorophyll b, and Carotenoids. • Each pigment absorbs different wavelengths of light.

9. Explain: Converting Sunlight into Sugar • Notice that chloroplasts absorb blue-violet and red-orange light very well. • The chloroplasts convert the absorbed light energy into chemical energy. • Why are leaves green? • Why do leaves change colors in the fall? • Complete Stop & Think #1-4 p. 329

10. Explain: Converting Sunlight into Sugar • Read “Making Carbon Compounds” p. 330-333 • Take notes! • Read “Energy Currency of Cells” p. 333 • Take Notes.